JP2009196455A - On-vehicle relay control unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an on-vehicle relay control unit which can prevent the freezing of a relay contact point without a significant change of the interior structure of an on-vehicle relay and without a consuming battery power supply. <P>SOLUTION: In a power supply circuit 10 of a vehicle, a control unit 15a is provided that extends self-shut-off time after an ignition switch is turned off when moisture caused by condensation etc. may be frozen on the relay contact point 12a under the outside temperature of 0°C or lower and when an ignition relay 12 is not sufficiently warmed up by the insufficient warming up of an engine. Thereby, the temperature of the relay contact point 12a is raised more even if the engine is not sufficiently warmed up, so that the temperature of the relay contact point decreases after the temperature of other portions drops. Therefore, the freezing of moisture caused by condensation etc. on a relay contact point 12a can be prevented without consuming the power supply of a battery 11 and without changing the interior structure of the ignition relay 12 significantly. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a control device for an in-vehicle relay, and particularly relates to prevention of icing of an ignition relay.

  During the self-shut off time after the ignition switch is turned on after the ignition switch is turned on, the exciting coil is energized and the relay contact is closed, and the power from the power supply is supplied to the load. Thus, an in-vehicle relay that opens a relay contact and stops the supply of power to a load is known.

  Conventionally, among such in-vehicle relays, in particular, in-vehicle relays (for example, ignition relays) through which a large current flows, an air-tight structure may be adopted for heat dissipation purposes and measures against air expansion inside the relay due to energized heat generation. It is very difficult. Further, since the relay contact is connected to a load (for example, an engine control unit) through a metal bus bar having an elongated rectangular cross section, the heat dissipation effect is good. Therefore, when the engine is sufficiently warmed up and the relay contact temperature is sufficiently high, it takes time for the relay contact to cool down and the temperature of the part (for example, the case) different from the relay contact is first. Therefore, it is unlikely that moisture such as condensation will freeze on the relay contacts. On the other hand, if the engine is not warmed up sufficiently and the relay contact temperature has not risen sufficiently, moisture such as dew condensation freezes thickly on the relay contact with good heat dissipation, resulting in contact non-conduction, that is, starting failure There was a problem that it was easy to produce.

Therefore, in order to solve such a problem, for example, in Patent Document 1, when a contact failure or abnormality occurs due to icing of the relay contact of the power feeding circuit, the relay temperature is increased by energizing the relay coil. Disclosing freezing is disclosed.
Patent Document 2 discloses that when icing is generated inside the relay, voltage application to the exciting coil is repeatedly applied and stopped to generate vibration at the freezing position to release the icing.
Japanese Patent Application Laid-Open No. H10-228688 discloses that the movable iron core of the electromagnetic lock device is prevented from freezing by applying a voltage to the exciting coil and the anti-freezing holding coil.

JP 2007-276552 A JP 2007-165406 A JP 2000-1000062 A

However, the above-mentioned former and middle ones are intended to recover contact discontinuity due to icing of the relay contacts and the like, and there is a problem that starting failure due to icing of the relay contacts cannot be prevented beforehand. .
In the latter case, when applied to an in-vehicle relay, it is possible to prevent icing of the relay contact, but since the energization is continued, the battery is consumed very much and the battery rises. There is a problem that the fuel consumption deteriorates. Furthermore, since a holding coil for preventing freezing is required, there is a problem that the internal structure of the in-vehicle relay must be significantly changed.

  The present invention has been made in view of such circumstances, and it is possible to prevent icing of the relay contacts without excessively consuming the battery without significantly changing the internal structure of the in-vehicle relay. An object of the present invention is to provide a control device for a vehicle-mounted relay.

In order to achieve the above object, according to the first aspect of the present invention, during the self-shutoff time after the ignition switch is turned on, the exciting coil is excited and the relay contact is closed, and the power from the power source is supplied to the load. When the self-shutoff time elapses, the exciting coil is de-energized, the relay contact is opened, and the on-vehicle relay control device stops supplying power to the load.
The outside temperature detected by the outside temperature detecting means is preset within the time of the outside air temperature detecting means for detecting the outside air temperature, the power source voltage detecting means for detecting the voltage of the power source, and the self shut-off time after the ignition switch is turned off. If the power supply voltage detected by the power supply voltage detecting means is not less than a preset predetermined value and the temperature of the in-vehicle relay is not more than a preset predetermined value, the self-shutoff time And a control means for extending the length.

  In order to achieve the above object, the invention according to claim 2 is characterized in that, in addition to the configuration of the invention according to claim 1, the temperature of the in-vehicle relay is estimated by using an elapsed time from the ignition switch ON to the ignition switch OFF. Alternatively, it is detected using temperature detecting means provided in the in-vehicle relay.

  According to the first and second aspects of the present invention, the outside air temperature is equal to or lower than a predetermined value and the power supply voltage is equal to or higher than a predetermined value within a self-shutoff time after the ignition switch is turned off. If the elapsed time after the ignition switch is turned on or the in-vehicle relay temperature is below a predetermined value set in advance, the self-shutoff time is extended to warm the relay contact longer. In other words, when the outside air temperature is low, the relay contact is not warmed sufficiently while the power supply is sufficient, and moisture such as condensation may freeze on the relay contact, the relay contact can be warmed for a longer time to The temperature of the other part (for example, the case) was lowered first than the temperature.

  As a result, the relay contact temperature drops after the temperature of other parts has dropped, so that moisture such as dew condensation does not occur on the relay without applying a load to the power supply and without significantly changing the internal structure of the in-vehicle relay. It becomes possible to prevent freezing on the contact. In addition, even if moisture such as condensation freezes on the relay contact, the temperature of the other part will drop first than the relay contact temperature, so the water will not freeze thickly and contact failure will occur There is no fear.

  According to the on-vehicle relay control device of the present invention, if there is a possibility that moisture such as condensation may freeze on the relay contact of the on-vehicle relay, the self-shutoff time is extended to warm the relay contact longer. As a result, the relay contact temperature is lowered after the temperature of other parts is lowered, so that moisture such as condensation is prevented from freezing on the relay contact. In addition, the battery is not excessively consumed, and the internal structure of the in-vehicle relay is not significantly changed.

  An in-vehicle relay control apparatus according to an embodiment of the present invention will be described in detail with reference to FIG. FIG. 1 is a block diagram showing an embodiment of a power supply circuit for a vehicle equipped with a vehicle relay control device of the present invention.

  As shown in FIG. 1, a vehicle power supply circuit 10 includes a battery 11 as a power source, an ignition relay 12 as an in-vehicle relay, a load 13, an ignition switch 14, and a control device 15.

  The battery (+ electrode) 11 is connected to the load 13 via the relay contact 12a of the ignition relay 12, and the relay contact 12a of the ignition relay 12 and the load 13 are connected via a bus bar (not shown). . The bus bar is an elongated bar-shaped member made of metal that is used in place of the conventional power supply line, and has a long and rectangular cross section, and therefore has a good heat dissipation effect. Further, the exciting coil 12 b of the ignition relay 12 is connected to the ignition switch 14 via the control device 15.

In the ignition relay 12, during the self-shutoff time after the ignition switch is turned on after the ignition switch is turned on, the exciting coil 12 b is excited and the relay contact 12 a is closed, and the electric power from the battery 11 is supplied to the load 13 (for example, an airflow sensor, A / F sensor, data link connector). When the self-shutoff time has elapsed, the exciting coil 12b is de-energized, the relay contact 12a is opened, and the supply of power to the load 13 is stopped.
The self-shutoff time is set by a control unit 15a described later or a self-shut relay or timer (not shown).

  The control device 15 includes a control unit 15a as control means, an outside air temperature sensor 15b as outside air temperature detecting means for detecting outside air temperature, and a battery sensor 15c as power source voltage detecting means for detecting the power supply voltage of the battery 11. It is configured.

  More specifically, the control unit 15a includes a microprocessor (not shown) and various input / output ports, and the central processing unit executes an application program firmwareized by a ROM, whereby each sensor 15b, 15c and an ignition switch. Condensation is achieved by continuing to excite the exciting coil 12b after the self-shutoff time has elapsed (continuously closing the relay contact 12a) and warming the relay contact 12a for a longer period of time based on various information data relating to ON / OFF of 12 Thus, it is possible to prevent moisture such as freezing on the relay contact 12a. Therefore, the control unit 15a includes an ON / OFF detection unit 15a1, a count unit 15a2, a timer unit 15a3, and a determination unit 15a4.

  The ON / OFF detector 15a1 is a detector that detects the ON / OFF state of the ignition switch 14 and outputs the detected value as information data.

  The count unit 15a2 measures the time when the ignition switch 14 is turned on based on the information data from the ON / OFF detection unit 15a1, that is, the elapsed time from the ignition switch ON to the ignition switch OFF, and determines the information data. To the unit 15a4. The count unit 15a2 sends information indicating that the ignition switch has been switched from ON to OFF as information data to the timer unit 15a3.

When the information data indicating that the ignition switch has been switched from ON to OFF is output from the count unit 15a2, the timer unit 15a3 is ignited only for a predetermined time (self-shutoff time) even if the ignition switch is OFF. Information data for exciting the 12 excitation coils 12b is output to the determination unit 15a4. Therefore, the control unit 15a is directly supplied with the power for driving the exciting coil from the battery 11, and can excite the exciting coil 12b of the ignition relay 12 even after the ignition switch is turned off. It has become.
Furthermore, as will be described in detail later, the timer unit 15a3 can extend the self-shutoff time by a predetermined time based on an information signal from the determination unit 15a4.

  Based on the information data from the count unit 15a2 and the timer unit 15a3, the determination unit 15a4 excites the excitation coil 12b and closes the relay contact 12a during the self-shutoff time after the ignition switch is turned on after the ignition switch is turned on. To relay control. The determination unit 15a4 performs relay control based on the information data from the timer unit 15a3 so that the excitation coil 12b is de-energized and the relay contact 12a is opened after the self-shutoff time has elapsed.

  Further, the detection value detected by the outside air temperature sensor 15b and the detection value detected by the battery sensor 15c are input to the determination unit 15a4, and information from the count unit 15a2 and the timer unit 15a3 is input. Together with the data, it is used for icing mode determination as to whether or not to extend the self-shutoff time.

  That is, the determination unit 15a4 determines that the detected value (outside temperature) detected by the outside air temperature sensor 15b during the self-shutoff time after the ignition switch is turned off is equal to or lower than a predetermined value (temperature at which freezing occurs, 0 ° C.). In addition, the detection value (battery voltage) detected by the battery sensor 15c is equal to or greater than a predetermined value set in advance, and the elapsed time after the ignition switch is turned on based on the information signal from the count unit 15a2 is equal to or less than the predetermined value set in advance ( For example, it is determined whether it is 10 minutes or less. That is, here, the relay temperature (relay contact temperature, hereinafter the same) is estimated using the elapsed time after the ignition switch is turned on, and it is determined whether or not the ignition relay 12 is sufficiently warmed.

  If all three conditions are satisfied, an information signal for extending the self-shutoff time set by the timer unit 15a3 is sent to the timer unit 15a3. On the other hand, if one of the three conditions is not satisfied, the self-shutoff time is set not to be extended.

  When determining whether or not to extend the self-shutoff time, the battery voltage is checked whether the ignition relay 12 is kept on for a predetermined time after the engine is stopped, or whether or not it adversely affects the next engine start. This is to determine whether or not.

The elapsed time after turning on the ignition switch is set to a predetermined value or less. If the ignition relay ON time is short, the relay contact 12a is not warmed, and moisture such as condensation is formed when the outside air temperature is 0 ° C. or less. This is because the relay contact 12a may freeze on the relay contact 12a, resulting in contact disconnection.
Instead of the elapsed time after the ignition switch is turned on, the relay temperature is detected by using a temperature sensor as temperature detecting means attached to the ignition relay 12 or its vicinity, and it is determined whether or not the ignition relay 12 is warmed. You may do it. However, in this case, since a temperature sensor has to be added, the manufacturing cost is higher than when the relay temperature is estimated using the elapsed time after turning on the ignition switch.

  The control unit 15a is directly supplied with drive power from the battery 11, and supplies drive power to the ignition relay 12, the outside air temperature sensor 15b, and the battery sensor 15c even after the ignition switch is turned off. It is possible.

  Next, relay control performed by the control unit 15a will be described with reference to FIG. FIG. 2 is a flowchart showing a control procedure of relay control performed by the control unit 15a of the same example.

  The control unit 15a starts relay control simultaneously with turning on the ignition switch, and performs relay control so that the exciting coil 12b of the ignition relay 12 is excited. The ignition relay 12 supplies the electric power from the battery 11 to the load 13 when the exciting coil 12b is excited to close the relay contact 12a.

  In step 10, it is determined whether or not the ignition switch 14 is turned off. Here, if the ignition switch 14 is ON instead of OFF, the process returns to Step 10. On the other hand, if it is determined that the ignition switch 14 is turned off, the process proceeds to step 11.

  In step 11, based on the information data read from the count unit 15a2 read immediately before the ignition switch is turned off and the detection values output from the various sensors 15b and 15c during the self-shutoff time after the ignition switch is turned off, the ignition switch is turned off. During the later self-shutoff time, the outside air temperature detected by the outside air temperature sensor 15b is 0 ° C. or less, the battery voltage detected by the battery sensor 15c is equal to or greater than a predetermined value, and the information signal from the counting unit 15a2 It is determined whether or not the elapsed time after the ignition switch is turned on is 10 minutes or less.

  Here, when any one of the above three conditions is not satisfied, the routine proceeds to step 12 where the normal self-shutoff time (that is, the self-shutoff time is not extended) is set, and after the self-shutoff time has elapsed. The relay control is performed so that the excitation coil 12b is de-energized and the relay contact 12a is opened.

  On the other hand, when all of the above three conditions are satisfied, the process proceeds to step 13, where it is determined that it is an icing mode in which moisture such as condensation may freeze on the relay contact 12 a, and the next step 14. In, the extension of the self-shutoff time is determined. Then, after the extended self-shutoff time has elapsed, relay control is performed so that the excitation coil 12b is de-energized and the relay contact 12a is opened.

Next, the operation will be described.
In general, when the outside air is low, the larger the cross-sectional area of the bus bar is, the faster the temperature of the bus bar is reduced when the relay is OFF, and the temperature is transmitted to the relay contact 12a via the relay terminal. Therefore, inside the relay, the temperature drop of the relay contact 12a and the metal part connected to the relay contact 12a occurs most rapidly, and there is an increased possibility that moisture such as condensation will freeze on the relay contact 12a.

  Therefore, when the outside air temperature is 0 ° C. or less, the control unit 15a determines whether or not the ignition relay 12 is not sufficiently warmed due to insufficient engine warming and moisture such as condensation may freeze on the relay contact 12a. If there is a possibility of icing, the excitation coil 12b of the ignition relay 12 is continuously excited by extending the self-shutoff time. Thereby, even if the engine is not sufficiently warmed up, the relay contact 12a is maintained in the energized state, so that the contact temperature is further increased. As a result, after the elapse of the extended self-shutoff time, the temperature of the part different from the relay contact 12a is lowered before the relay contact temperature, and moisture such as condensation freezes on the relay contact 12a. Will be prevented in advance. Further, even if condensation occurs on the relay contact 12a and icing occurs, the icing does not occur thickly as in the prior art, so that contact failure does not occur.

  In addition, the relay contact 12a is warmed so that the relay contact temperature decreases after the temperature of the other part is lowered, so that an excessive load is not applied to the battery 11. In addition, the internal structure of the ignition relay 12 is not significantly changed.

  As described above, according to the present invention, when moisture such as condensation may freeze on the relay contact 12a of the ignition relay 12 within the self-shutoff time after the ignition switch is turned off, the self-shutoff time Is extended to warm the relay contact 12a longer. As a result, the relay contact temperature is lowered after the temperature of other parts is lowered, so that moisture such as dew condensation is not consumed without depleting the battery 11 and without significantly changing the internal structure of the ignition relay 12. It is possible to prevent freezing on the relay contact 12a. In addition, even if moisture such as condensation freezes on the relay contact 12a, the temperature of the part other than the relay contact temperature falls first, so that the moisture does not freeze thickly and a contact failure occurs. There is no fear.

The in-vehicle relay is not limited to the ignition relay, and may be applied to other in-vehicle relays.
In addition, when the power supply circuit of the vehicle is already provided with a self-shutoff function by, for example, a self-shut relay or a timer, it is desirable that the timer unit 15a3 functions as a timer unit for extending the self-shutoff time. .

It is the block diagram which showed one Embodiment of the power supply circuit of the vehicle provided with the control apparatus of the vehicle-mounted relay of this invention. It is a flowchart which shows the control procedure of the relay control performed with the control unit of the example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Vehicle power circuit 11 ... Battery (power supply)
12 ... Ignition relay (in-vehicle relay)
12a ... relay contact 12b ... exciting coil 13 ... load 14 ... ignition switch 15 ... control device 15a ... control unit (control means)
15b ... Outside air temperature sensor (outside air temperature detecting means)
15c ... Battery sensor (power supply voltage detection means)

Claims (2)

During the self-shut off time after the ignition switch is turned on after the ignition switch is turned on, the excitation coil is energized and the relay contact is closed, and the power from the power source is supplied to the load. In the in-vehicle relay control device that is de-energized to open the relay contact and stop supplying power to the load,
An outside air temperature detecting means for detecting the outside air temperature;
Power supply voltage detecting means for detecting the voltage of the power supply;
Within a self-shutoff time after the ignition switch is turned off, the outside air temperature detected by the outside air temperature detecting means is equal to or less than a preset predetermined value, and the power supply voltage detected by the power supply voltage detecting means is preset. A control means for extending the self-shutoff time if the temperature is not less than a value and the temperature of the in-vehicle relay is not more than a predetermined value set in advance
An on-vehicle relay control device comprising:   The temperature of the in-vehicle relay is estimated by using an elapsed time from the ignition switch ON to the ignition switch OFF, or detected by using a temperature detecting means provided in the in-vehicle relay. In-vehicle relay control device.

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